Evaluation of Binder Aging and Its Influence in Aging of Hot Mix Asphalt Concrete: Technical Report [2014-04]

2014PDFTech ReportFHWA/TX-14/0-6613-1Project 0-6613Hot mix asphaltWarm mix paving mixturesBindersAging (Materials)OxidationAbsorptionAsphalt concrete pavementsMix designPavement designPavement performanceTexasTexas. Dept. of Transportation. Research and Technology Implementation OfficeDavison, RLiu, GuanlanRose, Avery A.Tong, YunweiGu, FanLing, MengArambula, EdithEstakhri, Cindy K.Lytton, Robert L.Texas A&M Transportation InstituteUnited States. Federal Highway AdministrationUS Transportation CollectionWarm mix asphalt (WMA) technologies, through reduced mixing and placement temperatures, have reduced fuel consumption, enhanced compaction, increased haul distances and an extended paving season. Issues of concern in WMA are binder oxidation and absorption and their impact on pavement durability. Key future work should combine results from this project with other recent TxDOT projects to develop a comprehensive and fundamentals based mixture design and pavement performance prediction methodology that accounts for climate, traffic loading, pavement structural properties, life-cycle cost analysis, and that is applicable to HMA, WMA, polymer-modified binders, and mixtures that incorporate RAP and RAS. Such an effort would be a major contribution to pavement design and is a realistic goal. Some other key findings are: 1) absorption is directly related to aggregate void fraction, 2) WMA absorption is somewhat less than HMA absorption, 3) the DGC provides a reliable and relatively easy measure of absorption for an aggregate/binder pair, 4) standard (ASTM) methods for measuring absorption can be problematic, depending on the level of absorption, 5) binders modified using warm mix technologies were found to have similar oxidation kinetics to their base binders, 6) the overlay tester and VEC measurements were successfully used to characterize mixture fatigue, 7) mixture fatigue resistance declines with binder oxidation, a result that is omitted entirely from typical pavement design guides (e.g., the MEPDG), and 8) during the first summer of its service life, oxidative aging, curing, and absorption have a significant beneficial effect on the performance of warm mixes.93